共查询到18条相似文献，搜索用时 234 毫秒
1.
2.
3.
蛹虫草是冬虫夏草最为理想的代用品,并且蛹虫草某些药用成分的含量高于冬虫夏草。在大量平行试验的基础上,对人工栽培的蛹虫草菌株进行筛选,以实验室为基础,得到较为完整的获得蛹虫草菌液的实验条件:组织分离育种选用实体上截中间或中间偏向顶端处菌种性能好;20℃~25℃温度范围内蛹虫草菌丝生长旺盛;虫草在进行菌丝发酵时碳源以蛋白胨为最优;菌种的保存:10℃/5℃(昼夜)、散射光,保藏30d,菌株表现为菌落边缘整齐,菌丝致密,菌丝长速均匀稳定,菌丝干重和子实体产量较高。 相似文献
4.
热带假丝酵母（Candida tropicalis）是长碳链二元酸发酵生产中的常用菌种,而热带假丝酵母突变株HP-2-48是一株高产DC12的优良生产菌株。本文对十二碳二元酸的发酵进行了研究,考察了青霉素钠盐、尿素、丙烯酸、pH值对菌体生长、产酸的影响并对其作用机制进行了讨论,并据此建立了长碳链二元酸新的发酵工艺。 相似文献
5.
6.
具有抑菌活性乳酸菌发酵条件的研究 总被引：1，自引：0，他引：1
以致病菌大肠杆菌、单细胞里斯特氏菌、金黄色葡萄球菌为指示菌,以乳酸菌SMN3-3为试验菌株,研究发酵条件对菌株SMN3-3发酵乳上清液抑菌效果的影响,试验结果发现,乳酸菌SMN3-3以5×106CFU/mL为接种量,37℃发酵24h,得到的发酵乳上清液的抑菌效果为最佳,结果表明,不同的发酵条件对乳酸菌SMN3-3抑菌效果有很大影响。 相似文献
7.
8.
试验以琯溪蜜柚为原料,选用酵母、醋酸杆菌作为发酵菌种进行液体发酵酿造柚子果醋,对复合果胶酶酶解、果汁脱苦、酒精发酵及醋酸发酵工艺进行研究,确定最佳加工工艺参数。酿制出来的沙田柚果醋颜色金黄,澄清透亮,醋味浓郁,同时具有琯溪蜜柚的特殊清香味。 相似文献
9.
用大肠杆菌（Ｅ．ｃｏｌｉ）乳糖发酵菌株（Ｌａｃ＾＋）,从基因水平探索元极堂内三元场的诱变效应。实验菌经二次处理,初步显示元极堂内三元场能诱发Ｅ．ｃｏｌｉ乳糖发酵基因突变,其突变率为２×１０＾－３￣０．１（物化因子诱变率１０＾－６￣１０＾－５）。突变率是高的,效果是明显的,从而为元极堂内三元场诱变育种提供了理论依据。 相似文献
10.
11.
从受油烟污染严重的土壤中分离到一株脂肪酶产量较高的菌株，通过统计实验设计的方法对发酵过程进行了优化。首先，通过Plackett-Burman设计实验，对影响产脂肪酶发酵的碳源、氮源、无机盐、pH、温度和转速等因素进行考察。通过实验，发现黄豆粉、K2HPO4和摇床转速对脂肪酶的产生影响较大。随后，利用曲面响应法中的中心点设计进行实验，以上述3个因素作为自变量。以发酵液的酶活作为响应，通过拟合最终得到了脂肪酶发酵的响应曲面函数。对该函数在一定的约束条件下求极值．得到了脂肪酶产率最大时的发酵条件。 相似文献
12.
BackgroundThe alga Laminaria japonica is the most economically important brown seaweed cultured in China, which is used as food and aquatic animal feedstuff. However, the use of L. japonica as a feedstuff in Apostichopus japonicas farming is not ideal because A. japonicas does not produce enough enzyme activity for degrading the large amount of algin present in L. japonica. In this study, semi solid fermentation of the L. japonica feedstuff employing a Bacillus strain as the microbe was used to as a mean to degrade the algin content in L. japonica feedstuff.ResultsThe Bacillus strain, Bacillus amyloliquefaciens WB1, was isolated by virtue of its ability to utilize sodium alginate as the sole carbon source. Eight factors affecting growth and algin-degrading capacity of WB1 were investigated. The results of Plackett–Burman design indicated that fermentation time, beef extract, and solvent to solid ratio were the significant parameters. Furthermore, the mutual interaction between the solvent to solid ratio and beef extract concentration was more significant than the other pairs of parameters on algin degradation. Optimal values obtained from Central-Composite Design were 113.94 h for fermentation time, 0.3% (w/v) beef extract and 44.87 (v/w) ratio of solvent to feedstuff. Under optimal conditions, 56.88% of the algin was degraded when a 50-fold scale-up fermentation was carried out, using a 5-L fermenter.ConclusionsThis study provides an alternative and economical way to reduce the algin content in L. japonica through degradation by WB1, making it a promising potential source of feed for cultured L. japonica. 相似文献
13.
酿酒酵母(Saccharomyces cerevisiae)的生长和发酵与其己糖转运蛋白家族紧密相关.酵母己糖转运蛋白家族包括Hxtlp至Hxt17p、Ga12p、以及同源蛋白Snf3p和Rgt2p这两个葡萄糖感应器.其中Hxt1p～Hxt7p对酵母生长及发酵发挥重要作用,缺失这7个蛋白的酵母无法从培养基中摄取己糖进行生长和发酵.根据对己糖的亲和力的不同,这几个转运蛋白可分为低亲和力转运子.包括Hxt1P和Hxt3p;高亲和力转运子,包括Hxt6p和Hxt7p;以及中等亲和力转运子Hxt2p和Hxt4p;而Hxt5p在生长发酵过程中没有发现有任何诱导表达.本文介绍了Hxt1p-Hxt7p等己糖转运蛋白在酵母生长发酵不同阶段中所发挥的作用,以期为构建高乙醇发酵效率的工业酵母菌株提供参考. 相似文献
14.
BackgroundIn industrial yeasts, selection and breeding for resistance to multiple stresses is a focus of current research. The objective of this study was to investigate the tolerance to multiple stresses of Saccharomyces cerevisiae obtained through an adaptive laboratory evolution strategy involving a repeated liquid nitrogen freeze–thaw process coupled with multi-stress shock selection. We also assessed the related resistance mechanisms and very high-gravity (VHG) bioethanol production of this strain.ResultsElite S. cerevisiae strain YF10-5, exhibiting improved VHG fermentation capacity and stress resistance to osmotic pressure and ethanol, was isolated following ten consecutive rounds of liquid nitrogen freeze–thaw treatment followed by plate screening under osmotic and ethanol stress. The ethanol yield of YF10-5 was 16% higher than that of the parent strain during 35% (w/v) glucose fermentation. Furthermore, there was upregulation of three genes (HSP26, HSP30, and HSP104) encoding heat-shock proteins involved in the stress response, one gene (TPS1) involved in the synthesis of trehalose, and three genes (ADH1, HXK1, and PFK1) involved in ethanol metabolism and intracellular trehalose accumulation in YF10-5 yeast cells, indicating increased stress tolerance and fermentative capacity. YF10-5 also showed excellent fermentation performance during the simultaneous saccharification and fermentation of VHG sweet potato mash, producing 13.40% (w/v) ethanol, which corresponded to 93.95% of the theoretical ethanol yield.ConclusionsA multiple-stress-tolerant yeast clone was obtained using adaptive evolution by a freeze–thaw method coupled with stress shock selection. The selected robust yeast strain exhibits potential for bioethanol production through VHG fermentation.How to cite: Zhang Q, Jin Y, Fang Y, et al. Adaptive evolution and selection of stress-resistant Saccharomyces cerevisiae for very high gravity bioethanol fermentation. Electron J Biotechnol 2019;41. https://doi.org/10.1016/j.ejbt.2019.06.003 相似文献
15.
文章根据人机材料方法环境,分析在中国北方的大型火力发电站失败的几个蒸汽涡轮机燃油喷射试验,同时阐述如何解决。 相似文献
16.
BackgroundXylitol is a five carbons polyol with promising medical applications. It can be obtained from chemical d-xylose reduction or by microbial fermentation of Sugarcane Bagasse Hemicellulosic Hydrolysate. For this last process, some microbial inhibitors, as furfural, constitute severe bottleneck. In this case, the use of strains able to produce xylitol simultaneously to furfural neutralization is an interesting alternative. A wild-type strain of Geotrichum sp. was detected with this ability, and its performance in xylitol production and furfural consumption was evaluated. Furthermore, were analyzed its degradation products.ResultsGeotrichum sp. produced xylitol from d-xylose fermentation with a yield of 0.44 g·g-1. Furfural was fully consumed in fermentation assay and when provided in the medium until concentration of 6 g·L-1. The furfural degradation product is not an identified molecule, presenting a molecular weight of 161 g·mol-1, an uncommon feature for the microbial metabolism of this product.ConclusionThis strain presents most remarkable potential in performing furfural consumption simultaneous to xylitol production. Subsequent efforts must be employed to establish bioprocess to simultaneous detoxification and xylitol production by Geotrichum sp. 相似文献
17.
BackgroundProdigiosin has been demonstrated to be an important candidate in investigating anticancer drugs and in many other applications in recent years. However, industrial production of prodigiosin has not been achieved. In this study, we found a prodigiosin-producing strain, Serratia marcescens FZSF02, and its fermentation strategies were studied to achieve the maximum yield of prodigiosin.ResultsWhen the culture medium consisted of 16.97 g/L of peanut powder, 16.02 g/L of beef extract, and 11.29 mL/L of olive oil, prodigiosin reached a yield of 13.622 ± 236 mg/L after culturing at 26 °C for 72 h. Furthermore, when 10 mL/L olive oil was added to the fermentation broth at the 24th hour of fermentation, the maximum prodigiosin production of 15,420.9 mg/L was obtained, which was 9.3-fold higher than the initial level before medium optimization. More than 60% of the prodigiosin produced with this optimized fermentation strategy was in the form of pigment pellets. To the best of our knowledge, this is the first report on this phenomenon of pigment pellet formation, which made it much easier to extract prodigiosin at low cost. Prodigiosin was then purified and identified by absorption spectroscopy, HPLC, and LCMS. Purified prodigiosin obtained in this study showed anticancer activity in separate experiments on several human cell cultures: A549, K562, HL60, HepG2, and HCT116.ConclusionsThis is a promising strain for producing prodigiosin. The prodigiosin has potential in anticancer medicine studies.How to cite: Lin C, Jia X, Fang Y, et al. Enhanced production of prodigiosin by Serratia marcescens FZSF02 in the form of pigment pellets. Electron J Biotechnol 2019;40. https://doi.org/10.1016/j.ejbt.2019.04.007 相似文献
18.
苯酚降解菌株FY-6的初步鉴定及苯酚降解特性的研究 总被引：4，自引：0，他引：4
苯酚降解菌株FY-6经形态观察和生理生化反应鉴定为假单胞菌(Pseudomonas sp.).对不同温度、pH以及不同苯酚浓度培养基中菌株的生长和苯酚降解效率进行了研究.结果表明,FY-6菌株能在无机盐培养基中以苯酚为唯一碳源和能源进行生长,并同时对苯甲酸和萘有一定的降解作用.在温度为25～40℃、pH6～9和苯酚浓度400～1400 mg/L范围内,FY-6菌株的生长及苯酚降解效率均达到较高水平,因此,初步认定该菌株能适应较广泛的环境条件,并对苯酚浓度具较高的耐受性. 相似文献